Any info on the new Audio Research VS115 tube amp?

I have just bought a VS115 with LS17. This is an addition to my Jeff Rowland Concentra Integrate MK2. My speakers are Sonus Faber Guaneri Homage (the original one). My CD player is Audio Resolution modified by Great Northern Sound.

Without running in the new pre and power amps, I noticed some significant improvements in the sound qualities, deeper depth, wider stage, clarity, transparency, tighter bass, and most important a very neural sound allowing hours and hours of un-fatigue listening. I am listening with a big smile :)

I have a question regarding the bias adjustment. There are 8 x 6650C tubes, and there are 8 pairs bias checking ports (4 of them for V1, V5, V2 & V6 are marked 'Set V# 65mA', and 4 of them for V3, V8, V4 & V7 are marked 'Check V# 57mA-73mA' where # is the corresponding valve number) at the back. But there are only 4 bias adjusting holes at the top of the cover. So how does the bias adjusting work? When I am adjusting the bias, which bias testing pair should I be using? FYI, there are bias adjusting holes between V7 & V5, V3 & V1, V4 & V2, and V6 & V8.

Normally, I expect to have one bias adjusting hole for each pair of bias testing port. Maybe VS115 bias adjustment is for a matched pair?

Your advise is appreciated

Hi Basile,

So, you can only adjust 4 of the 8 tubes. In fact, I adjusted V1 to be 65mV but V3 then measures at 77mV. Do I then tune down V1 so that V3 falls within the advertised range of 57mV and 73mV?

Anyway, I found out that my VS115's right channel is causing my speaker to crackle (noises within the hiss), quite noticeable even during the day time. I even swap all tubes between right and left channels. The crackling still comes from the right channel. So probably not faulty and bad tubes. I tried all sort, changing power cable, use different sockets in my house. With my Jeff Rowland, no crackling just very low hiss.

Anyway, it is going back to the dealer, a 5 hours round trip though.